The Seldinger technique has become an accepted procedure for placing a catheter in a blood vessel. The technique involves first inserting a hollow needle into the blood vessel, advancing a guide wire through the hollow needle into the blood vessel, and then extracting the needle over the wire leaving the guide wire in place. A catheter can then be moved along the guide wire and into the blood vessel before the guide wire is removed.
Guide wires used for the above mentioned technique are usually made from stainless steel and include a tightly coiled spring wrapped around one or more axial core wires. Some guide wires have a very flexible pre-bent tip with a rounded leading end to facilitate insertion and to minimize the risk of damage to blood vessels as the wires are fed through these vessels. This type of guide wire (known as a "J" guide wire) is fed through a guide which is only slightly larger so that the pre-bent end is held straight as the wire is fed through the needle and into the blood vessel.
Guide wires, because of their length, are commonly packaged in a coiled tube dispenser to make handling less cumbersome. Also, the coil assists in keeping the wire in the sterile field. However insertion from the coil into a needle requires the use of one hand to hold the needle and an engagement piece guiding the wire into the needle while the other hand grips the wire between the coil and the engagement piece to move the wire forward from the coil into the needle.
It would be preferable to be able to advance the wire using one hand and this problem has been addressed in U.S. Pat. Nos. 4,860,757 and 5,125,906. These patents disclose devices in which a long guide wire is held in a flexible coiled tube having several turns so that the wire can be advanced from the Cube through a dispensing head and through the needle. The device must be gripped in a pinching action while the thumb is free to be used to advance the guide wire. These devices are somewhat awkward to hold and to use with one hand.
It is therefore an object of the invention to provide an improved hand operated guide wire advancement device which can be operated and easily controlled in one hand.